The purpose of this paper is to analyze the legality of the rental of furnished real estate through digital platforms. It develops, fundamentally, four factors that lead to conclude its illegality: (i) infringement of the property rights of other co-owners, (ii) commercial exploi-tation of real estate for residential use, (iii) conduct constituting unfair competition, and (iv) abuse of rights. In particular, it studies how the simultaneous and relevant non-compliance with tax, labor, sectorial, and other legislation, which leaves an offeror in an improved posi-tion, constitutes unfair competition conduct under article 3 of the law on unfair competition. Technological disruption, innovation and new contracting modalities that favor users must be welcomed, but under equal conditions for all competitors or suppliers. Although, as the paper will show, it is an unregulated activity, this does not put it outside the legislation and the legis-lation of similar acts should be applied as in the case of all unnamed contracts.